I'm a bassoonist and when I play in a wind band I often get given a trombone part.
Sometimes I have to transpose a score because it is in E♭𝄞. And sometimes I have to transpose passages that are too high for me to play. I won't be of a standard to play the solos in Rite of Spring anytime soon. So I find myself writing out a lot of scores in a different clef or octave.
My notation reference (Gould, Behind bars, 72) tells me that this is an "open tie" which is also indicated laissez vibrer.
Now, I understand what this means for a stringed instrument. It means "don't damp the string at the rest".
But my reed won't continue vibrating when I stop blowing, and I must assume something similar applies to trombones.
So clearly the notation doesn't really mean laissez vibrer: it's some sort of metaphor. Can anyone explain what it does mean?